135 



The teeth in the lower jaw are the root and base of the crown of the incisor (i), and 

 the entire carnassial (p 4). 



I was thus still driven, as far as these specimens went, to an inferential conclusion as 

 to the form of the crown of the anterior incisor, both above and below. But, since pre- 

 paring for the Royal Society (Philosophical Transactions, 1871, p. 213) a description of 

 the specimens, I have been favoured by photographs and fossils of both these teeth 

 nearly complete, and also with a plaster cast of the entire lower incisor, now in the 

 Museum of Natural History at Sydney, New South Wales, through the kindness of the 

 Trustees of that Museum and of their able Curator, Mr. Gerard Krepft, Corr. M.Z.S. 



The teeth transmitted and the subjects of the photographs were obtained from the 

 Breccia-cave in Wellington Valley*, in the course of recent assiduous researches con- 

 ducted by Alex. M. Thomson, D.Sc, Reader on Geology, Sydney University, and by 

 Mr. Krefft, in 1869, aided by the liberal grant of £200 voted by the Local Parliament 

 of New South Wales in favourable response to the Memorial which I addressed to the 

 Colonial Secretary, February 23rd, 1867 f. 



Whatever interpretation may ultimately be accepted in palaeontology of the habits 

 and affinities of Thylacoleo, additional and valuable materials for such interpretation 

 have thus been added to the subjects of former descriptions: an account of these addi- 

 tions, with their bearing on the arguments that have been opposed to my conclusions, 

 is given in the present section. 



Upper Jaw and Maxillary Teeth. — The specimen of this part of the skull (Plate VII.) 

 includes almost the entire premaxillary (figs. 1-5, 22), with its alveolar [a, a'), nasal (n), 

 and palatal ( p) portions. 



The alveolar portion contains the socket (a) of the anterior large laniariform incisor 

 (i 1), that of a much smaller incisor (i 2) opening close to the first, and, after an interval 

 of two lines, the front half of the socket (c) of a small canine (fig. 9), the division of 

 which socket is made, or rather indicated, by the premaxillo-maxillary suture (s, s') : 

 this third socket is rather larger than the second, and is more outwardly placed. 



The nasal portion of the premaxillary forms anteriorly, above the deep socket of the 

 first incisor, a thick obtuse margin (fig. 4, 22), convex transversely, concave vertically and 

 also laterally toward the nasal cavity (ib. n) ; it becomes much thinner above the socket, 

 then regains thickness at its upper part, where the plate arches inward to join the nasal 

 bone. A ridge (r) for the attachment of the inferior " turbinal " divides the fore part of 

 the nasal chamber into an upper and a lower (n 1 ) passage. 



The palatal process (figs. 2 & 3, p 22') is thick and short ; it projects forward about 

 four lines in advance of the first large alveolus (fig. 1, j|>$), is grooved above, lengthwise, 



* Discovered by Colonel Sir Thomas Mitchell, C.B., F.G.S., and described in his work, < Three Expeditions 

 into the Interior of Eastern Australia,' 8vo, vol. ii. 1838. 

 t See page 239 of the present work. 

 X As shown in the subject of fig. 1, Plate xvin. 



4* 2 



